1. Field of the Invention
The present invention relates to a light pen for detecting a selected display event and for producing an actuating response thereto. More particularly, the present invention relates to a light pen wherein light from a light source is propagated along a light conductive fibre cable for processing at a remote location.
2. Description of the Prior Art
Light pens for detecting display events and for producing actuating signals responsive thereto are well known and of many types. Typically, such light pens are of cylindrical shape and include a tip portion which may be pressed to a selected display location by a user. Light produced by the display at that location is coupled to an internal photo detector or to a fibre optic cable, by which the light is transmitted to a remotely located photoelectric device. Such prior art light pens are exemplified by the device entitled "Pressure Actuated Light Pen", U.S. Pat. No. 4,109,146, issued to Hillman on Aug. 22, 1978. A more recent type of light pen, including a fibre optic cable and a switching device, is described in pending U.S. patent application No. 400,796 now U.S. Pat. No. 4,490,607, entitled "Fibre Optic Light Pen," filed July 22, 1982, and assigned to IGT Corporation of Reno, Nevada, the assignee of the present invention.
Light pens are often used in hostile environments, such as bars, casinos, and classrooms. In gaming applications, for devices such as video poker machines and the like, light pens are often placed by careless users in ashtrays full of partially extinguished smoking materials and beverage glasses which may still retain amounts of a partially consumed liquid refreshment. Such light pens are often the subject of abuse resulting from emotional disappointment accompanying a loss. Needless to say, light pens are regularly damaged and often need to be replaced. The need for constant servicing of damaged light pens is an expense that reduces the profitability to the casino operator of the associated gaming device. Light pens have also been expensive to manufacture. The gaming device manufacturer may pay between $350-400 to purchase a prior art type light pen, only to replace it after a gamester has thoughtlessly left the pen partially submerged in the contents of a beverage container.